The proteins involved in the clotting cascade, including, e.g., Factor VII, Factor VIII, Factor IX, Factor X, and Protein C, are proving to be useful therapeutic agents to treat a variety of pathological conditions. Accordingly, there is an increasing need for formulations comprising these proteins that are pharmaceutically acceptable and exhibit a uniform and predetermined clinical efficacy.
Because of the many disadvantages of using human plasma as a source of pharmaceutical products, it is preferred to produce these proteins in recombinant systems. The clotting proteins, however, are subject to a variety of co- and post-translational modifications, including, e.g., asparagine-linked (N-linked) glycosylation; O-linked glycosylation; and γ-carboxylation of glu residues. These modifications may be qualitatively or quantitatively different when heterologous cells are used as hosts for large-scale production of the proteins. In particular, production in heterologous cells often results in a different array of glycoforms, which are identical polypeptides having different covalently linked oligosaccharide structures.
In different systems, variations in the oligosaccharide structure of therapeutic proteins have been linked to, inter alia, changes in immunogenicity and in vivo clearance. Thus, there is a need in the art for compositions and methods that provide clotting protein preparations, particularly preparations comprising recombinant human Factor VII, modified Factor VII, or Factor VII-related polypeptides, that contain predetermined glycoform patterns.